Feed switch



Nov. 26, 1957 J. L. JOHNSTON FEED SWITCH U m M m WM am m 0 1 m H f m Mn Nov. 26, 1957 J. L. JOHNSTON Filed May 21. 1954 FEED SWITCH Joseph L. Johnston, Detroit, Micln, assignor, by mesne assignments, to the United States of America as represented by the Secretary of the Army Application May 21, 1954, Serial No. 431,310

6 Claims. (Cl. 89-135) My invention relates to revolver-type automatic weapons and more particularly to an electrical firing system therefor including a switch for safeguarding the weapon against the failure of extraction of a discharged cartridge case.

The revolver-type weapon includes a barrel with a recoil unit supporting the barrel slidably disposed on a receiver. A drum including cartridge chambers with corresponding t-angential index rollers is rotatably disposed on the recoil unit to successively convey the chambers to similarly spaced stations including a firing station with the chamber axially aligned with the barrel. An actuator, engageable with the rollers, reciprocatcs with respect to the recoil unit to rotate the drum responsive to discharge of cartridges in the firing position chambers. The

cartridges are half-rammed and finish-rammed into the chambers in the two stations preceding the firing station, respectively, by an arm and a plunger of an actuator rammer.

The weapon is supplied by an external electric circuit and the supply is externally controlled for discharging the cartridges chambered in the firing station.

An extractor pivoted on the recoil unit removes the spent cartridge cases from the station following the firing station, responsive to forward strokes of the actuator. If for any reason the extractor fails to remove a spent cartridge case, the chamber is rotated to the ram position as usual, and the rammer attempts to force an additional cartridge into the chamber, causing damage to the weapon. This condition is known as double-feeding the weapon.

It is an object of my invention, therefore, to provide the weapon with a device for controlling a circuit of the weapon responsive to the position of :a chamber of the drum.

An additional object of my invention is to provide such a weapon with a safety device for controlling an operating circuit switch responsive to rotation of a cartridge to a particular station of the chambers.

A further object of my invention is to provide the weapon with an electric circuit control switch responsive to rotation of a cartridge case to the extraction station of the chambers.

A still further object of my invention is to provide a safety device for stopping the weapon upon failure of extraction of a spent cartridge case from the drum of the weapon.

Other aims "and objects of my invention will appear from the following explanation thereof.

In carrying out my invention, an automatic weapon is provided with a switch having a pair of contacts connected in the firing circuit of the weapon. An arm, pivoted in the axis of the drum, is biased to a normal position for engagement of the contacts to complete the circuit. The arm is serially responsive to rotation of a cartridge to the extraction station to disengage the contacts and to extraction of the case from the drum for reengagement of the contacts to again operate the weapon.

For a more complete understanding of my invention,

2,814,235 Patented Nov. 26, 1957 attention is directed to the following description and accompanying drawings in which:

Fig. 1 is a partial elevational view of a revolver-type automatic weapon incorporating my invention;

Fig. 2 is a view along the line 22 of Fig. 1; and

Fig. 3 is an exploded view, from the front, of the firing system of the weapon.

According to the drawing, a weapon 12 includes a receiver 14 with a recoil unit 16 slidably disposed thereon. Recoil unit 16 includes a barrel 18 and a drum 20 provided with a rear face 21 and rotatably mounted on a shaft 22, journaled in recoil unit 16. Drum 20 includes cartridge chambers 26 with corresponding tangential in-- dex rollers 28.

Receiver 14 includes a cylinder 30 enclosing a piston 32 having a plunger 34 secured thereto. A passage 36 connects cylinder 30 to the bore of barrel 18. An actuator 38, slidable with respect to recoil unit 16, is biased by springs 40 engaging a rear wall 42 of receiver 14 to a battery position for engagement with plunger 34.

Actuator 38 includes grooves for engaging rollers 28 to rotate drum 20 and successively convey chambers 26 to corresponding stations including a firing station, in which chambers 26 are axially aligned with barrel 18, and an extraction station 44 adjacent to the firing station responsive to discharge of cartridges chambered in the firing station.

Figs. 1 and 2, each show a chamber 26 in extraction station 44 and in Fig. 1 a cartridge case 46 is shown in chamber 26 disposed with primer end 48 of the case projecting from drum 20. Cases 46 are removed from the extraction station chamber by an extractor 49 pivoted on recoil unit 16 and operated responsive to a cam disposed on actuator 38.

The weapon includes an electric circuit having a connector 50 on recoil unit 16 for engagement with an external direct current supply 51 and the weapon is fired by externally controlling supply 51. Conductor 52 is connected between the grounded negative of the supply and the frame of recoil unit 16. A positive conductor 54 is connected through contacts 56 of a firing switch 58 and contacts 60 of a feed switch 62 to a firing. pin 64 insulated from recoil unit 16. Conductor 54 is led to and from contacts 60 and to firing pin 64 through tubes 68 and 70, respectively. Contacts 60 are mounted on an insulated block 71 of recoil unit 16. A blade 72 of firing switch 58 is disposed on actuator 38 for engagement with contacts 56 to close the firing circuit in the battery position of the actuator and drum 20 is grounded to the frame of recoil unit 16, as schematically shown at 74.

Drum 20 is rotated to convey live cartridges to the firing station in contact with firing pin 64 and simultaneously to convey cases 46 of the cartridges to the extraction station responsive to consecutive portions of the rearward and forward strokes of actuator 38. Extractor 49 is operated to remove the cases from dru'm 20 re sponsive to the later portions of the forward strokes of actuator 38.

An arm 76 of feed switch 62 is rotatably disposed on shaft 22 adjacent rear face 21 and biased to a normal position for engagement with primer end 48 of a cartridge case in rotation between the firing station and the extraction station by a spring 78 secured in a hole 80 of recoil unit 16 and bearing against a pair of shoulders 82 and 84, of arm 76. In the normal position of the arm, a blade 86 thereof engages contacts 60 to close feed switch 62.

As a case 46 is conveyed to extraction station 44, arm 76 is rotated responsive to the rotation of drum 20 and blade 86 is carried out of engagement with contacts 60 to open feed switch 62 for fail safe operation of the weapon. When the extraction station case 46 is removed from drum 20 by extractor 49, arm 76 is returned to the normal position by spring 78 to reengage contacts 60 and blade 86.

It is readily apparent that operation of the weapon is immediately discontinued upon failure of extraction.

Although a particular embodiment of the invention has been described in detail herein, it is evident that many variations may be devised within the spirit and scope thereof and the following claims are intended to include such variations.

I claim:

1. In a weapon including a drum provided with spaced chambers for engaging the cases of cartridges and rotatably disposed for conveyance of the chambers to correspondingly spaced stations, and in electric circuit for discharge of the cartridges in the first of the stations including a switch, a device comprising a member biased to a normal position of interference with a case chambered in the other of the stations to close the switch and complete the circuit and disposed for displacement from said normal position responsive to rotation of the cases of the discharged cartridges to the other station to open the switch and break the circuit.

2. A weapon comprising a drum provided with spaced chambers for engaging the cases of cartridges and rotatably disposed for conveying said chambers to similarly spaced stations including a firing station and an extraction station, an electric circuit including a switch for discharge of a cartridge chambered in said firing station, and a device including a member biased to a normal position to close said switch and disposed for displacement from said normal position to open said switch and discontinue operation of the weapon responsive to rotation of the case of the cartridge to said extraction station.

3. In a weapon including a drum provided with spaced chambers for engaging the cases of cartridges and rotatably disposed for conveying the chambers to serially disposed stations including a firing station and an extraction station, and an electric circuit for discharge of a cartridge chambered in the firing station, a mechanism for operating the circuit comprising contacts connected in the circuit and a device biased to a normal position for engagement of said contacts to complete the circuit and disposed for response to rotation of the case of the cartridge to the extraction station for disengagement of said contacts to break the circuit and discontinue the operation.

4. A device for controlling operation of a weapon including a barrel, a slidable recoil unit for supporting the barrel, a drum provided with spaced chambers for engaging the cases of cartridges and a shaft and rotatably disposed on the recoil unit for serially conveying the chambers to stations spaced similarly thereto including a firing station and an extraction station, an electric circuit for operation of the weapon to fire cartridges chambered in the firing station, and a mechanism for extraction station removal of the cases of the cartridges from the drum, said device comprising a member rotatably disposed on the shaft and biased to a normal position of interference with a case in the extraction station, and a switch disposed between the recoil unit and said member and connected to complete the circuit in said normal position, said member being responsive consecutively to the rotation of a case to the extraction station to open said switch and to the removal of the case from the drum to close said switch and complete the circuit for resumption of the operation.

5. In a weapon including a slidable recoil unit, a drum provided with a shaft and spaced chambers for engaging the cases of cartridges and rotatably disposed on the recoil unit for serially conveying the chambers to stations spaced similarly thereto including a firing station and an extraction station, an electric circuit for discharge of cartridges chambered in the firing station, and a mechanism for extraction station removal of the cases from the drum, a device for controlling the electric circuit comprising an arm rotatably disposed on the shaft for normal position interference with a case in the extraction station and provided with a pair of stops, a spring for engagement between said stops and the recoil unit for biasing said arm to said normal position, and contacts electrically connected in the circuit and disposed between said arm and the recoil unit for normal position engagement to com plete the circuit, said arm being serially responsive to rotation of the case to the extraction station to disengage said contacts and discontinue the circuit and responsive to removal of the case from the drum to reengage said contacts and complete the circuit.

6. In a weapon including a recoil unit, a drum pro vided with cartridge chambers and a shaft and rotatably disposed on the recoil unit, an actuator biased to a battery position and disposed for operation in rearward andforward strokes from and to the battery position for successive displacement of the chambers from a firing station to an extraction station responsive to discharge of cartridges in the chambers, an extractor pivoted on the recoil unit for removal of the cases of the cartridges from the drum responsive to the operation, a firing pin disposed for engagement with the primers of cartridges chambered in the firing station, and a member rotatable on the shaft including an arm spring-biased to interference with cartridge cases chambered in the extraction station, an electric circuit comprising branches disposed for respectively connecting the lines of an outside power source with the firing pin and the drum, and firing and feed switches series connected in one of said branches and disposed for engagement with the recoil unit and for respective engagement with the actuator and the member to complete the circuit and elfect the discharge responsive to the forward strokes and to the removal.

References Cited in the file of this patent UNITED STATES PATENTS 2,380,455 Lippert et al. July 31, 1945 FOREIGN PATENTS 288,467 Switzerland May 16, 1953 

